The present invention relates to an encoder device for converting movement such as rotation into an A/D conversion signal, and more particularly, to an encoder device for use with a zoom lens barrel or the like of a camera.
An encoder device for use with a zoom lens barrel or the like has been proposed in Japanese Laid-Open Patent Application Sho No. 62-180338, for example. Such an encoder device reads out a resistance division A/D conversion encoder which performs A/D conversion of an output from a resistance printed pattern or a digital pattern.
With the digital encoder described above, however, a number of ports are required when used in a CPU. In addition, with the resistance division A/D conversion encoder, variations in power voltage and printed resistance should be taken into consideration, resulting in difficulty in obtaining a stable encoder value.